FIELD OBSERVATIONS OF DISPERSION, MATING AND DEVELOPMENT OF AMORBUS-OBSCURICORNIS (WESTWOOD) (HEMIPTERA, COREIDAE)

Aspects of the behaviour and development of Amorbus obscuricornis were observed in the field during spring and summer 1994/1995 at a site in southern Tasmania. Nymphs of A. obscuricornis remained predominantly on host plants on which they were initially observed for much of their development. Some movements between hosts occurred with migrating nym phs ranging in age from second to fourth instar. Most adults observed for the first time on hosts were males, a number of which were later r ecorded with females. Males were observed to have longer host residenc e times (7-56 days) than females (less than or equal to 7 days). Compl ete nymphal development was roughly estimated to take considerably few er degree-days under fluctuating field temperatures than at constant t emperature. This suggested that other mechanisms (e.g. basking) may si gnificantly influence nymphal growth and development.